1784. Where litigious rights are sold, the person from whom they are claimed is fully discharged by paying to the buyer the sale price, the costs related to the sale and interest on the price computed from the day on which the buyer paid it.
This right of redemption may not be exercised where the sale is made to a creditor in payment of what is due to him, to a coheir or co-owner of the rights sold or to the possessor of the property subject to the right. Nor may it be exercised where a court has rendered a judgment affirming the rights sold or where the rights have been established and the case is ready for judgment.